Process of condensing formaldehyde compounds



Patented Dec.v 17, 1940 when STATES PATENT orFiCE 2,224,910 raoosss or CONDENSING roammauxna com-owns William E. Hanford and Richard S. Schreiber, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del, a cor- I poration of Delaware No Drawins- Application August 25, was, Serial No. 226,730

20 Claims. (Cl. 260-594) tions, one yielding hydroxy-aldehydes and ketones and the other a Cannizzaro reaction involving the formation of formic acid and methanol. O. Loew (J. prakt, chem. 34, 51 (1886)), one of the earliest workers in'this field, states that considerable amounts of formic acid and methanol are formed if the formaldehyde concentration exceeds 1 to 2%, regardless of the propedure or catalyst used. Other workers in this field have stated that the Canniz zaro reaction predominates when the formaldehyde concentration exceeds 4 to 5%. The substitution of methanol for the aqueous medium has been one of .the expedients su gested for inhibiting the Cannizzaro reaction, and thus raise the yields of desired condensation products. In alcoholic media formaldehyde has been successfully condensed to hydroxy-aldehydes and ketones in concentrations exceeding 5%. over methanol as the condensing medium (1) for economic reasons since it involves substitu tion of a cheap for a relatively expensive solvent, (2) because it does not introduce complicating side reactions, e. g; acetal and ether. formation,

and (3) because the condensation reaction goes' faster in water than in alcohol. Theretofore no practical process has been developed wherein water can be used. By the use of. the invention described herein,

formaldehyde inaqueous media inconcentrations exceeding 8% is successfully condensed to give high yields of hydroxy-aldehydes and ketones. It is evident therefore that this invention marks a definite advance in the artof formalde- 0 hyde condensation to hydroxy-aldehydes and ketones.

This invention has as its object to provide a process for condensing formaldehyde in concentrated aqueous solutions to hydroxy-aldehydes and ketones in high yields. Another object is .to provide a method for controlling the rate of condensation of formaldehyde to hydroxy-aldehydes and ketones. A further object is to condens formaldehyde in concentrated solutions to low moleculan weight hydroxy-aldehyd es and ketones. A still further object is to.provide a process for condensing formaldehyde in aqueous solutions containing at least 8% formaldehyde.

Another obiect is to provide a method for con- 4 trolling the rate of condensation of formaldehyde Water is preferredafter as adjuvants.

to low molecular weight hydroxv-aldehydes .and ketones in solutions containing at least 8% formaldehyde. Still another object is to make possible the use of small amounts of catalystin the reaction involving the condensation of formaldehyde. Another object is to prolong the life or the catalyst used in the reaction involving the condensation of formaldehyde. Another object is to depress the Cannizzaro reaction, and aid the condensation reaction. Another object is to provide. means for regenerating the catalyst durin'g condensation of the formaldehyde. Still another object is tocontrol and direct the course of the condensation of formaldehyde to hydroxyaldehydes and ketones. A still further object is to afford a method for obtaining high yields of such compounds as glycerol, ethylene glycoh.

and erythritol from formaldehyde. Other objects will appear hereinafter. 7

These objects are accomplished by the invention which is described in full herein and which is not limited except as defined in the claims annexed hereto.

It has been found that high yields of hydroxy 25 c'm ca or a'compound capable of enolizing, rearranging, d or hydrolyzing to give products having such a g ping. The presence of the enediol makes ible the suppression of the Cannizzaro reaction and assists in the condensation of the formaldehyde when said formaldehyde is present in concentrations exceeding 8%. a

It has also been found that the rate of reaction is susceptible of careful control by regulation of the pH of the reaction mixture through addition of alkaline materials of inorganic or organic origin. These materials added for the primary purpose of functioning as hydrogen ion concentration regulators are referredto herein- It has further been found that these. adjuvants, in addition to making it 7 possible to regulate ,the' rate of reaction, also For example, if the condensaton is carried. out

at a pH of fromv 7 to 8 the condensation is complete in about 10 to 15 minutes, whereas at a pH of from 2.5 to 3.0 approximately 90 hours are required for the completion of the condensation. Furthermore, the addition of the adjuvant makes it possible to reduce the amount of catalyst from about 10% on the basis of the formaldehyde used to 2% or less. In order to obtain high yields o low molecular weight hydroxy-aldehydes and ketones, it is necessary to interrupt the reaction before all the formaldehyde has been condensed. Generally it is preferred to stop the condensation reaction when 40% to 95% of the formaldehyde has disappeared. If desired, however, the reac-. tion may be allowed to proceed until all the formaldehyde has disappeared. When the desired degree of condensation has been obtained, further reaction may be prevented either by chilling the solution to between 0 and 15 C. or by acidifying with a mineral or with a strong organic acid.

The discovery that the rate andcourse of the reaction may be controlled by properly adjusting the hydrogen ion concentration is applicable not only to condensation reactions in which the form-' aldehyde is .condensedin an aqueous medium and. in concentrations in excess of 8%, but to all type reactions in which the formaldehyde is insolution in a polar solvent.

The adoption of any one or more of these improvements results in a marked advance in the art of condensing formaldehyde to hydroxy-al'dehydes and ketones.

By carefully controlling the hydrogen ion concentration and by carrying out the catalytic condensation in the presence of an enediol and an adjuvant, hydroxy-aldehydes and ketones can be obtained in yields varying from 90 to 98%, based on the formaldehyde condensed. By subjecting 40 these condensation products to catalytic hydrogenation, such valuable industrial products as ethylene glycol, glycerol, erythritol, etc., are obtained.

In order to illustrate more specifically this invention there are given below examples which set forth certain well defined instances of its application. These examples, however, are not to be considered as limitative since many modifications may be made without departing from the spirit and scope of this invention.

Example I Three hundred grams of paraformaldehyde were suspended in 300- grams of water (50% CHaO) and the mixture warmed to C. when 2 cc. of a 10% sodium hydroxide solution was added to aid in depolymerizing the paraformaldehyde. The temperature of the reaction mixture was then raised to 99 0.. when 66 cc of a solution containing 26 grams of enediols was added. When the temperature again reached 99 C., 6 grams of lead oxide were added and 10% sodium hydroxide added at such a rate as to maintain a pH of 7 during the entire run. Immediately after the addition of the lead oxide catalyst, a vigorous reaction set in and external heating was discontinued. When 82% of the formaldehyde had con densed, further reaction was prevented by chilling the solution and adding 2 cc. of concentrated sulfuric acid dissolved in 10 cc. of water. The time required for attaining this degree of condensation was approximately 12 minutes. The amount of 10% sodium hydroxide added to maintain a pH of 7 was approximately 98 cc. The preas indicated by its inertness to hot Fehlings solu-.

tion. After removal of the nickel catalyst by filtration, the resulting solution was concentrated at atmospheric pressure to approximately 200 cc., and then distilled under reduced pressure to remove the ethylene glycol which boils at 83 to 88 C. at 5' to 6 mm. pressure. The residue which was viscous and showed a pronounced tendency to foam, was absorbed on asbestos and steam distilled at to C. under a pressure of 30 mm. Such a treatment. for three hours completely removed the glycerol and erythritol which was collected by condensing the distillates. The aqueous distillate was concentrated to 100 cc. at atmospheric pressure, and fractionally distilled at 5 to 6 mm. pressure to separate the glycerol and erythritol which boil at 150 to 158 C. and

to 215 C., respectively, at this pressure. The yields of polyhydric alcohols, based on the formaldehyde condensed were as follows:

Percent Polyhydnc alcohol Grams yield Ethylene glycol l2 l4. 6 Glycer 22. 5 27. 4 Erythritcl 13 16 Higher polyhydric alcoh 34. 5 42 From the per cent yield of polyhydric'alcohols givenabove, the percentage composition of the mixture of hydroxy-aldehydes and ketones may be calculated as being 14% glycol aldehyde, 27% glyceric aldehyde-dihydroxy acetone mixture, and 16% erythritol.

' Example II Five hundred grams of paraformaldehyde were sulfate removed by filtration, and the solution made neutral to methyl red with sodium hydroxide. An aliquot of this solution was hydrogenated as in Example I, and the product worked up in a similar manner. The following yields of polyhydric alcohols were obtained: ethylene glycol 16.2%; glycerol 27.8%; and 18% of higher polyhydric alcohols. v

The above experiment was repeated except that the condensation reaction was carried outat 80 C. instead of 50 C. The reaction required 85 minutes for conversion of 57% of the formaldehyde to a mixture of hydroxy-aldehydes and ketones, as compared to 32 hours for a 62% conversion at the lower temperature. The yields of ethylene glycol, glycerol, erythritol, and higher polyhydric alcohols, were 9%, 20%, 25%, and 20% respectively.

Example III Two hundred grams of paraformaldehyde c. After 80 minutes, 71% of "with 2 cc. of 10% sodium hydroxide.

raised 99 were suspended in 120 grams of water (02.5% 01-120) and depolymerized by warming to 99 C. with a trace of trimethylamine. To the solution was then added 30 cc. of a solution containing 12 grams of enediols, the temperature raised to 100 C., and 4 grams of lead oxide added. At the same time a 30% solution of trimethylamine was allowed to drop into the reaction mixture at such a rate that a temperature of 100 to 101 C. was

tion and of 105 to 108 C. toward the end. After about 25 minutes, 7.4% of the formaldehyde had been condensed and at this stage further condensation was prevented by adding 5 cc. of concentrated sulfuric acid in 15 cc. of water. The precipitatedlead"sulfate was filtered, the solution neutralized to methyl red with 10% sodium hydroxide, and the'products worked up as in Example I.

Analogous results were obtained when the above example was duplicated using sodium hydroxide in place of the trimethylamine.

Example IV" Two hundred grams of parai'ormaldehyde were suspended in 120 grams of water (02.5% C1120). and depolymerized by warming to 90 C. with trace of calcium hydroxide. To this solution was added 25 cc. of a solution containing 10 grams of enediols. After several minutes 4 grams of lead oxide were added and then small amounts of solid calcium hydroidde at such a rate as needed to keep the reaction proceeding vigorously. At the end of 35 minutes of the formaldehyde had condensed, during which time 2.5 grams of calcium oxide had been added. Further reaction was prevented by chilling the solution and adding 2 cc. of concentrated sulfuric acid dissolved in 10 cc. of water. The precipitated calcium and 46 lead sulfates were filtered oil, the solution made neutral to litmus with 10% sodium hydroxide,

and the products worked up as in Example I.

Analogous results were obtained when the above example was duplicatedlusing sodium hy- 5 droxide in place of the calcium hydroxide.

Example V '5) and treated exactly as in th above example, ex- 7 cept that 10 grams of magnesium oxide were .used in place of the calcium hydroxide. With this particular catalyst external heating was necessary to maintain a temperature at 100 to 101 the formaldehyde had condensed during which time 62 cc. of 10% sodium hydroxide were added to keep the solution alkaline to methyl red. The solution was chilled and 1 cc, of concentrated sulfuric acid in 5 cc. of water added. After filtering, the solution was neutralized to phenolphthalein with 10% sodium hydroxide. and the products worked up as in Example 1.

Example VI Three hundred grams of paraformald'ehyde were suspended in. 300 grams of water (50% 01-120) and depolymerized by warming to C.

The temof the reaction mixture was then C., 66 cc. of a. solution containing 26 grams of 'enediols were added, and then 6 grams of lead oxide, and 10% sodium. hydroxide at such a rate as to maintain a pH of 4.6 during the entire run. When 82% of the formaldehyde had perature ",coridensd, further reaction was prevented by maintained during the early stages of the mac-- glycol obtained was 6.5%

hydric alcohols 38%.

chilling ,the solution and adding 2 cc. of concen- Thetime required for obtaining this degree of condensation was minutes and the amount of 10% sodium hydroxide added to maintain the pH at 42.6 was 38 cc. The precipitated lead sulfate was removed by filtration, and the filtrate made neutral to litmus with 10% sodium hydroxide. An aliquot of this solution was hydrogenated as in Example I, and the products worked up in a similar manner. The following yields of polyhydric alcohols were obtained: ethylene glycol 13.3%; glycerol 22%; erythritol 20% and higher polyhydric alcohols i0%.

The above example wasduplicated, except that the pH was maintained at 2.8 throughout the entire run. Under these conditions approximately 90 hours were required for 10% of the formaldehyde to condense. The yield of ethylene and of higherpoly- Example VII To twelve hundred and fifty cc. of 40% formalin were added 750 cc. of water (20% (31-120) and the mixture heated to 90 C. At this point '75 cc. of a solution containing 35 grams of enediols was added. The temperature was raised 99 C. and 10 grams of lead oxide added. Immediately following the additionof the lead oxide, 10% of sodium hydrordde was allowed to run in at such a rate'that 45 cc. were added during the course of minutes. At the end of this time 75% of the formaldehyde had condensed. The solution was chilled and 5 cc. of concentrated sulfuric acid in 10 cc. of water were added to prevent further reaction. The precipitated lead sulfate was iil' tered, and the filtrate neutralized to methyl red with 10% sodium hydroxide. solution was hydrogenated as in Example I and the product worked up in a similar manner. The following yields of ,polyhydric alcohol were obtained: ethylene glycol 13.6%; glycerol 28%; and erythritol 24%.

Example VIII Two hundred grams of paraformaldehyde were suspended in 1800 grams of water (10% CHzO) anddepolymerized by warming to 80 C. with a trace of alkali. 30 grams of lead oxide and 2 grams of glyceric aldehyde. After holding the temperature at 80 C. for 2 hours 496% of the formeldehyde had disappeared. The solution was then chilled and treated with 25 grams of concentrated sulfuric acid in '75 cc. of water. The lead sulfate precipitate wasremoved by filtration, and the solution carefully treated with barium hydroxide until it no longer gave a positive test for sulfate ions. After a second filtration the solution was hydrogenated as in Example I, and the product worked up in a similar manner. The hydrogenated product was found to consist of 1% ethylene glycol; d% glycerol; 8.5% erythritol; and 70% of higher polyhydric alcohols. i

- Example IX One hundred ninety grams of paraformalde- I hyde were suspended in 210 grams of water and To the solution was then added An aliquot of this required approximately 19 cc.

condensed. The time required to obtain this degree of condensation was 68 minutes. When this degree of condensation had been reached the solution was chilled to 35 C. and the pH raised to 9.0 by the addition of 10% sodium hydroxide. Almost immediately after the pH had been raised to 9.0, the condensation began as indicated by a fairly rapid rise in the temperature of the reactionmixture. At the end of 63 minutes, during which time a small amount of 10% sodium hydroxide had been added to maintain the desired pH, 83% of the formaldehyde had been polymerized. The solution was then acidified with dilute sulfuric acid and the precipitated lead sulfate removed by filtration. Catalytic hydrogenation of the reaction mixture was carried out as in Example I and the product worked up in a similar manner. The following yields of polyhydric alcohols were obtained: ethylene glycol, 4.1%; glycerol, 17.1%; and erythritol, 21.8%.

Example X 10% sodium hydroxide was added to raise the pH to 7.0 where it was held by the further addition of alkali until the formaldehyde had been completely condensed. The time-required to complete this reaction was approximately two hours. The products were worked up as in Example I.

- Example XI Three hundred sixteen grams of paraformaldehyde were suspended in 350 grams of water and depolymerized by heating to 90 C. At this point 100 cc. of a' solution containing 30 grams of enediols was added. Several minutes after the addition of this material '30 grams of lead formate,

were added all at once, and the pH raised to 6.0 by the addition of 10% sodium hydroxide.v This The temperature was then quickly raised to 98 C. and the pH maintained at 6.0 until 80% of the formeldehyde had' disappeared. The time required to reach this degree of condensation was approximately 30 minutes. After removal. of thelead ions by precipitation as lead sulfate, an aliquot of this material was hydrogenated as described-in Example I. The initial pH of this solution, as determined by means of aglass electrode, was 7.5

' and the pH at the conclusion of the ..ydrogenation was 6.5 indicating that little or no acidity of enediols. Immediately after the addition of the enediol mixture, 10% sodium hydroxide was added to raise the pH to 7.0 where it was maintained until allof the formaldehyde had condensed. During the first part of the reaction it was necessary to use external heat in order to maintain a temperature of 97 to 99 0., although during the latter part the reaction became sufficiently exothermic so that the external heating could be dispensed with. The time required for the complete disappearance of the formaldehyde under these conditions was 47 minutes. The products were worked up as in Example I.

Although in the foregoing examples formaldehyde and paraformaldehyde have been used, it is to be understood that in the practice of this invention any form of formaldehyde or any formaldehyde derivative capable of liberating formaldehyde under the reacting conditions may be used. When using paraformaldehyde or trioxymethylene it is not essential to depolymerize same to formaldehyde as they may be used as such in the form of a suspension. When it is desired to depolymerize the paraformaldehyde or trioxy- .methylene it is not essential to add an alkali, as

the paraformaldehyde or trioxymethylene may be depolymerized by merely heating at approximately 100 C. for about one hour.

Thepreferred adjuvant is sodium hydroxide; for'example, in runs where 10% lead oxide is required to obtain the desired degree of condensation the amount may be decreased to 2% or less by adding to the reactants 2% or less of sodium hydroxide, preferably during the course of the condensation. Besides sodium hydroxide, potassium hydroxide, sodium carbonate, calcium oxide, calcium carbonate, magnesiumv oxide, calcium sulfite, sodium bisulfite, magnesium carbonate, trimethylamine, triethylamine, pyridine, etc., may .be employed with a high degree of success.

The preferred catalysts are metallic lead and its compounds, e. g., oxide, hydroxide, nitrate, formate, etc., metallic tin andits salts, e. g., chloride, formate, etc., calcium compounds, e. g., oxide, hydroxide, chloride, etc. In place of'the preferred catalysts such compounds as barium, magnesium, and cerium oxides and hydroxides, cerium chloride, thorium nitrate, etc. can be used with almost equally good results. The use of basic calcium and magnesium compounds as catalysts is illustrated in Examples IV and V, respectively. The amount of catalyst required for efficient operation of this process depends to some degree on several factors such as the concentration of formalydehyde, the temperature used, the hydrogen ion concentration of the mixture, the amount and type of adjuvant present,

and the concentration of enediol employed. While amounts of catalyst as low as 0.01% ms ,be used, it is generally preferrednot to use lee" than 0.15%, based on the formaldehyde, because,

'when too small amounts are used, the reaction is sluggish and incomplete. In actual practice it is preferred not to use amounts of catalyst in excess of about 20 mol per cent, based on the formaldehyde.

As previously pointed out, the enediols are compounds having the grouping C= Iii-"- ts on or compounds which are capable of enolizing, rearranging, or hydrclyzing to give products having such a grouping. Among such products are glucose, ascorbic acid, fructose, benzoin, glycolic aldehyde, dihydroxyacetone, glyceric aldehyde,

erythrose, reductone, invert sugar, and the mixture of hydroxy-aldehydes and ketones produced by partial condensation of formaldehyde which consists essentially of glycolic and glyceric aldehydes, tetroses, hexoses, etc.,. along with some unchanged formaldehyde. Theamounts 0! aldehyde. The use of'more than 10% or enediol or its equivalent usuallyofiers no advantage.

It is generally desirable to add the enediol just prior to" the addition of the catalyst; however, this is not essential. Both the catalyst and the enediol may be added at the same time. Its.

. single phase is desired, the catalyst may be dissolved in the enediol by shaking atrocm or below room temperature for 5 to minutes, and then filtering to remove any undissolved material. The resulting filtrate will serve "nicely'as a source of both the enediol and catalyst.

If desired, the reaction may be initiated at from about 80 to about 105 C. and at a pH within the range of 2.5 to 8.0, and then continued at a temperature of 45 to 80 (3., but at a higher pH; namely, 6.0 to 12.0. It is generally preferred to operate at a controlled pH of from 5.0 to 9.0 and at a temperature of 45 to 105 C. The method of addingalkali to control the hydrogen ion concentration of the resulting solution. .will vary depending upon whether or not it is desirable to maintain a given hydrogen ion concentration throughout the reaction. 1

When the desired degree of condensation has been attained, further reaction may be prevented either by chilling the solution to from 0 to 15 C. or by acidifying with a mineral acid or with a strong organic acid or by using both of these expedients. The use of such acids as sulfuric and, oxalic is preferred as they facilitate the removal of leadand calcium catalysts asinsoluble sulfates and oxalates. V The hydroxy-aldehydes and ketones obtained by this process maybe used as such as intermediates in the synthesis of valuable industrial products or may be catalytically hydrogenated 40 by any method adapted for the catalytic hydrogenation of unsaturated oxygen-to-carbon 1-11;

ages. The conditions of temperature and pres= sure employed in any one case will of course vary" with the catalyst used and the process selected. In general,the-hydrogenation reaction may be carried at temperatures ranging from 20 to 175 C. and at pressures'in excess of 30 atmospheres. In the preferred practice of the-invention temperatures in the range'of to 139 C. and pres- 5o sures in excess of 200 atmospheres are generally employed. Any hydrogenation catalyst may be used, but it is generally preferredto use metallic 1 nickel or cobalt either in the massive form or supported on .such materials as meselguhr or as silica gel. Other types of hydrogenation catalysts that are practicalfor use in this reaction are platinum and the oxides and chromites of hydrogenating metals such as cobalt, niclrehcopper,

. ,etc. I y 60 Provided the pH of the crude mixture. of hydroxy aldehydes and keton is maintained in excess of 6, the hydrogenatio reaction proceeds I without undue catalyst consumption even in the.

presence of considerable free formaldehyde. From the hydrogenated product the various de sirable components may beseparated by any conventional means such'as fractional distillation; The crude mixture obtained from the catalytic hydrogenation may be used in any applications I employing glycerol or other polyhydric alcohols,

e. g., in nitration reactions, in the preparation of p lyhydric alcohol-polycarboxyli acid resins,

' etc.

v. I By "formaldehyde compound as we use the termi in the claims, we mean formaldehyde and such fodehyde liberating substantial amounts of formaldehyde under the reacting conditions described hereinabove.

It is apparent that many widely different exn bodiments of this invention may be made without departing from the spirit and scope thereof and therefore itis not intended to be limited ex cent as indicated in the appended claims. We claim:

l. A process for preparing hydroxy-aidehydes and hetones from formaldehyde compounds in yields of at least 60%, based on the weight or the formaldehyde compound converted, charac...

ketones formed.

3. A process for condensing 8. formaldehyde compound while. in aqueous solution of at least 8% -'concentration, which comprises mixing an enediol with the formaldehyde compound solu tion prior to bringing same under condensation conditions, condensing same at a controlled hy drogen ion concentration, stopping the reaction when the desired degree of condensation has taken place, and recovering the mixture of hy= derivatives as are capable of drox'y aldehydes and ketones from thereactlon mixture.

d. A process which comprises condensing formaldehyde in an amount of'at least 8% in a liquid menstruum comprising essentially water in the presence of an ion of an element selected from group IV and from subgroup A of group II in the periodic table and of an alkaline regulator for the pH of the reaction mixture and an enediol, said reaction being further characterized in that it is carried out under a controlled hydrogen ion concentration, and furtherin that the reaction is stopped when the desired degree of condensation has taken place and the mixture of lwdroxy-aldehydes and ketones recovered.

5. The process for the preparation of low molecular weight hydroxy-aldehydes and ketones which comprises condensing formaldehyde in aqueous solution in amount ofat least 8% in the presence of an enediol, said enediol being in ad= mixture with the formaldehyde prior to the start of the condensation of said formaldehyde, and I in the presence of an ion of an element selected from group IV and from subgroup A of group II in the periodic table, and an alkaline regulator for the pH of the reaction mixture, said reaction being characterized in that the pH is adjusted to between 5.0 and 9.0, and further in that the reaction is stopped when between 40 and of the formaldehyde has become condensed.

6. The process in accordance with claim 5 characterized in that the condensation is carried out inthe presence of lead monoxide and sodium hydroxide. 1

7. The process in accordance .with claim 5 characterized in that the enediol is present in the starting reactants in the amount of .at least 11% by weight of the formaldehyde.

8. A process which comprisgcondensing form aldehyde while in an aqueous solution in an amount of at least 8% in the presence of lead monoxide and an alkaline regulator for the pH of the reaction mixture comprising essentially sodium hydroxide and with at least one enediol present in the starting material, the total enediols present in the starting -material being in an amount of about 1 to about 10% by weight of the formaldehyde present, said condensation reaction being characterized in that the pH is controlled and maintained within the range of 5.0 to 9.0, and further in that the reaction is stopped when between and 95% of the formaldehyde has been condensed and the mixture of hydroxyaldehydes and ketones formed recovered.

9. A process for condensing a formaldehyde compound in aqueous solution in an amount greater than 8%, which solution is of such composition that heating will cause the conversion of said formaldehyde compound to formic acid and methyl alcohol, the improvement of directing the reaction so as to produce hydroxy aldehydes and ketones which comprises bringing into admixture with said formaldehyde compound solution an enediol and condensing said formaldehyde compound in the presence of said enediol. 10. The process in accordance with claim .9, characterized in that the condensation reaction is carried out in thepresence of an ion of an element selected from group IV and from sub-group A of group II of the periodic table.

11. The process in'accordance with claim 9 characterized in that the condensation reaction is carried out in the presence of an ion of an element selected from group IV and from subgroup A of group II of the periodic table and in the presence of an alkaline regulator for the pH of the reaction mixture.

12. The process in accordance with claim 9 characterized in that the condensation reaction is carried out in the presence of an ion of an element selected from group IV and from subgroup A of group II of the periodic table and in the presence of an alkaline regulator for the pH of the reaction mixture, stopping the reaction when the desired degree of condensation has taken place, and recovering the mixture of hydroxy aldehydes and ketones formed.

. 13. A process of condensing a formaldehyde compound in aqueous solution in an amount greater than 8%, which solution is of such composition that heating will cause the conversion of said formaldehyde compound to formic acid and methyl alcohol, the improvement of directing the reaction so as to produce hydroxy aldehydes and ketones which comprises bringing into admixture with the reactants an enediol, condensing said formaldehyde compound in the presence of said'enediol, and catalytically hydrogenating the resulting mixture at a pH within the range of 5 to 9. e

14. The process in accordance with claim 13 iaracterized in that the condensation reaction is carried out in the presence of an ion of an element selected from group IV andfrom subgroup A of group II of the periodic table.

15. The process in accordance with claim 13 characterized in that the condensation reaction is carried out in the presence of an ion of an element selected from group IV and from subgroup A of group II of the periodic table and in the presence of an alkaline regulator for the pH of the reaction mixture.

16. The process in accordance with claim 13 characterized in that the condensation reaction is carried out in the presence of an ion of an element selected from group IV and from subgroup A of group II of the periodic table and in the presence of an alkaline regulator for the pH of the reaction mixture, stopping the reaction when the desired degree of condensation has taken place, and recovering the mixture of hydroxy aldehydes a: :l ketones formed, prior to hydrogenating same.

17. A process for preparing polyhydric alcohols which comprises heating a formaldehyde compound in aqueous solution in an amount greater than 8% to a temperature of about 90 C. and then adding to said formaldehyde solution an enediol, raising the temperature of the mixture to about 99 C. and adding lead oxide, then adding to said mixture a solution of sodium hydroxide, chilling the solution after the condensation reaction has reached the desired stage and precipitating the lead catalyst by the addition of sulfuric acid thereto, filtering the precipitate and heating the resulting mixture to a temperature of 120 C. and under a hydrogen pressure of 2000 to 3000 lbs. per sq. in. while in the presence of a nickel hydrogenation catalyst.

18. A process for preparing hydroxy aldehydes and ketones which comprises heating a formaldehyde compound in aqueous solution in an amount greater than 8% to a temperature of about 90 C. and then adding to said formaldehyde solution an enediol, raising the temperature of the mixture to about 99 C. and adding lead oxide, then adding to said mixture a solution of sodium hydroxide thereby causing the condensation of said formaldehyde compound to hydroxy aldehydes and ketones.

19. A process for preparing polyhydric alcohols which comprises bringing an aqueous forms aldehyde-solution containing at least 8% formaldehyde to a temperature of 90 C., adding an enediol to said solution and then adding to said solution lead formate, adjusting the pH of the solution to 6.0 by the addition of a sodium hydroxide solution, then raising the temperature of the solution to 98 C. and maintaining a pH of 6.0 until 80% of the formaldehyde is condensed, precipitating the lead as lead sulfate thus separating same from the hydroxy aldehydes and ketones formed and catalytically hydrogenating the resulting mixture of hydroxy aldehydes and ketones by bringing same in admixture with hydrogen in the presence of a nickel-catalyst at a temperature of 120 C. and a pressure of 2000 to 3000 lbs. per sq. in.

20. A process for the manufacture of hydroxy aldehydes and ketones which comprises bringing an aqueous formaldehyde solution containing at least 8% formaldehyde to a temperature of 90 0., adding an enediol to said solution and then adding to said solution lead formate, adjusting the pH of the solution to 6.0 by the addition of a sodium hydroxide solution, then raising the temperature of the solution to 98 C. and maintaining a pH of 6.0 until 80% of the formaldehyde is condensed thereby causing the condensation of said formaldehyde compound to hydroxy aldehydes and ketones.

WILLIAM E. HANFORD. RICHARD S. SCHREIBER. 

